Fearless Leader was one of the villains on the 1960s cartoon series Rocky and His Friends and The Bullwinkle Show, both shows often collectively referred to as Rocky and Bullwinkle. Fearless Leader's true name was never given during the show's run.
Fearless Leader was the dictator of the fictional Eastern European nation of Pottsylvania, and the employer of the inept spies Boris Badenov and Natasha Fatale . However, it seems evident that he did answer to one man himself---the diminutive Mr. Big . Mr. Big appeared in two storylines of the series, "Upsidaisium" and "Metal Munching Moon Mice."
As expected from his position, Fearless Leader was a strict, ruthless character, and often harshly criticized the incompetence of his main minion Boris.
During the series' original run, Fearless Leader was usually a fairly minor character, but in the 2000 live-action/animated feature The Adventures of Rocky and Bullwinkle, he was played by actor Robert DeNiro, and his role was greatly expanded.